1. Field of Invention
The present invention relates to a condensate overflow prevention apparatus for use with an air cooling system, and in particular to a condensate overflow prevention apparatus that uses a pump.
2. Description of Related Art
An air cooling system, such as an air conditioner or a heat pump, typically has heat exchange coils that produce condensate as the system cools the air in a building. The condensate can cause damage to structures within the building, such as dry walls, ceilings, wooden supports, etc. Thus, the condensate is collected in a drain pan usually placed below the heat exchange coils, and is transported away through a drain line connected to the drain pan. Over a period of time, a blockage can occur in the drain pan or the drain line due to debris, algae, mold, etc. The blockage causes the condensate to accumulate in the drain pan, and eventually, overflows to cause damage to the building.
U.S. Pat. No. 5,069,042 discloses a condensate trap that includes a mechanical switch and a float. When the condensate accumulates in the trap due to a blockage, the float rises with the rising level of the condensate. Eventually, the float activates the mechanical switch to shut off the air cooling system to prevent further condensate from being produced by the system.
U.S. Pat. No. 5,522,229 discloses a drain tube that includes an inlet end for attaching to a drain pan, and an outlet end for transporting condensate out of the drain pan. The drain tube includes a sensor probe that extends from the drain tube inlet end and into the drain pan when attached to the drain pan. The sensor probe detects excess condensate in the drain pan due to a blockage. When the excess condensate is detected, the sensor probe triggers a control circuit that generates an output signal to sound an alarm and/or turn off the air cooling system.
U.S. Pat. No. 5,755,105 discloses a sensor apparatus having an inlet end which attaches to the drain pan. The sensor includes a pair of water contact points at the inlet end, and when fluid or water makes contact with the points, the points become conductive, closing a circuit between the contacts. A signal is generated and is transmitted to the air cooling system to shut off the system. The sensor apparatus includes a fluid high level indicator light, which glows when this event occurs.
U.S. Pat. No. 6,442,955 B1 discloses a condensate overflow safety switch included in a T- or L-shaped tubular structure which attaches to a drain pan. The switch is electrically connected to a circuit of an air cooling system, a power circuit or an alarm circuit. The switch has an annular float containing an annular magnet mounted about a tube in which a reed switch is sealed. The float moves up and down based on the level of the liquid within the tubular structure. Depending upon a predetermined level of liquid within the tubular structure, the float will move along the tube to open or close the reed switch to either shut off the air cooling system or to activate an alarm.
U.S. Pat. No. 5,323,620 discloses an air conditioner condensate sump pump controller that controls a pump for periodically pumping condensate out of a sump. The sump pump controller includes a lower positioned positive temperature co-efficient (PTC) resistor and a higher positioned PTC resistor in the sump. When the condensate reaches the level of the lower positioned PTC resistor, the pump is activated to pump the condensate out of the sump. However, if the condensate reaches the level of the higher positioned PTC resistor, this indicates a blockage within the conduit to the pump or malfunction in the pump itself. The sump pump controller then shuts down the air conditioner to prevent further formation of the condensate.
A known drain pan pump has an encapsulated pump and electronic circuitry within a plastic housing. The drain pan pump sits on a floor of a drain pan and is activated when water is present in the drain pan. The drain pan pump is deactivated when the water has been pumped away.